Besides the fact that the stuff invariably begins to peel sooner or later - leaving you with the fun task of removing the rest, you can't polish the chrome underneath it.
More importantly, if you can't polish the chrome underneath, you can't burnish off any rust that forms from neglect. I give you Exhibit A, one 1991 Masi Nuova Strada:
I rest my case. Nothing personal against Jim Allen, of course - with exception to these stays, the rest of the paint on this thing is phenomenal.
P.S.: I tried Ray Dobbin's cable lining trick under the BB on this MASI. It works well, even though the guides are open at the bottom.